I'm adding the driving fog lights to my barracuda. I know the factory used a relay , is there any reason I can not just go from battery to fuse to switch to lights? I'm not worried about not being factory correct this car has other modification.

You could but now you will have an additional switch to worry about switching off. As well without the relay your driving lights could be on when your headlights are at high beam. Why not wire in a relay? They are inexpensive and don't take a lot longer to install.
My 2 cents

I would not recommend using a 70 2947772 or 71 3488447 road lamp switch to directly power the road lamps. The reason is their internal contacts are small 1/8” wide oval head copper rivets and will arc when they are turned on and could cause the switch to fail. Relay contacts were typically 1/4” wide flat stainless steel to help prevent the current swing from arcing.

70 Cuda road lamps were manual on and off, meaning they were not wired through the 2889916 relay to receive power only when the low beams were turned on. They remained on whether the low or high beams were on. The 71 road lamps were wired differently through the 3513557 relay for power when the low beams were turned on only and would turn off when the high beams were turned on, then back on when the low beams were turned back on, just like new cars today.

Jim

I build a stand alone relay kit for the 70-71 roadlamp cars. It's everything that you need for under the hood. Only thing you would need would be a small, low amp trigger wire and switch to turn them on. I can set up a trigger wire into the passenger compartment if need be. I do everything to the customer spec if it's viable solution.

The roadlamps on a 70 can be on in either high or low beam. The 71 roadlamp relay turns the roadlamps off when high beams are switched on. It's a Fed regulation IIRC, that you can't have more than 4 forward facing illuminating lights on a vehicle.

It's the green wiring in this picture